1. Field
The present invention relates generally to air carts and air seeding equipment. More specifically, embodiments of the present invention concern an air cart with a metering assembly that includes independently powered metering wheels in a common meter body.
2. Discussion of Prior Art
It is well known by those of skill in the art that agricultural air carts and air seeding equipment are used to discharge seed and/or fertilizer in a field. In general, an air cart with one or more product tanks (to carry seed and/or fertilizer) is advanced along the field with an air seeding implement having a series of ground-engaging openers. The air cart meters a flow of seed and/or a flow of fertilizer to each opener through pressurized pneumatic conveying lines as the air cart and implement are being advanced. For each tank, the air cart includes a metering device with a series of metering wheels to dispense multiple flows of seed or fertilizer. The dispensed particulate flows are then carried by respective conveying lines to the openers.
Some of the known metering devices have metering wheels on a common shaft so that the wheels rotate with each other at the same speed. Other known metering devices having metering wheels that can be engaged and disengaged independently of the other wheels (e.g., so that particulate flows can be selectively provided to the openers). Some known metering devices have metering wheels with a flow rate that can be adjusted independently of the other wheels.
However, conventional air carts and metering devices have a number of deficiencies. For instance, metering devices with metering wheels on a common shaft are limited to discharging particulate flows at the same material flow rate. That is, such devices generally do not permit the metering wheels to be engaged, disengaged, or adjusted independently of the other wheels.
Prior art metering devices with independent metering wheels are mechanically complex and prone to mechanical failure. For instance, these devices have a series of pressurized metering bodies that each contain a meter wheel to dispense a respective flow of granular material. Each meter wheel is driven by a dedicated transmission mounted outside of the meter body. The pressurized metering bodies of these known devices are prone to leakage of pressurized air, which can impact the operability of the air cart. Furthermore, the exposed transmissions experience harsh environmental conditions that exacerbate failure of transmission components.